Rock-drilling machinery.



No. 633,692. Patented Sept. 26, |899.v W. GLEESON.

ROCK DRILLING MACHINERY.

(Application filed Apr. 19, 1899.)

(No Hode.)

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llNrTnD STATES PATENT Orrlca VILLIAM GLEESON, OF SAN FRANCISCO, CALIFORNIA.

ROCK-DRILLING MACHI'NERY.

SPEFICATION forming part of Letters Patent No. 633,692, dated September 26, 1899.

Application filed April 19, 1899.

To all 107mm 'it may conocrn':

Be it known that I, WILLIAM GLEESON, a citizen of the United States, residing at San Francisco, county of San Franciscoi and State of California, have invented certain new and useful Improvements in Rock-Drilling Machines and I hereby declare the Vfollowing to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to rock-drilling machines impelled by air or steam and to certain improvements therein whereby their efiiciency and rate of working are increased.

My improvements consist in devices whereby the stroke of the pistons of such machines and of the drills attached thereto can be instantly changed from a long to a short range and the reverse, such devices consisting of a means for pressing elastically against the distributing or slide valve and moving it in one direciion independently of the action of the tappet or other device for moving the valve normally or at full stroke and means for throwing said auxiliary means into or out of operation at the will of the operator. Said improvement is complemeutary to the device forming the subject of my application for Letters Patent copending herewith, filed November 9, 1898,8erial No. 695,951,which com prises a species of the same invention.

In the present form of the invention I employ a spring-pressed stem as the agent for pressing elastically against the slide-valve, or spring-pressure in any form, and show a simple mechanical cam -lever for throwing the spring-pressure into or out of action, as illustrated in the drawings filed herewith, forming a part of this specification.

Referring to the said drawings, Figure'Iis a longitudinal section through a rock-drilling machine provided with my improvements. Fig. II is a plan view of the valve-Chamber of the same.

A is a main cylinder of the usual construction provided with ports or passages B for the Operating fluid and adapted to receive an elongated piston O, composed of two Sections or heads Dvand E, that fit closely in the bore of the cylinder A.

G is the valve-box, provided With a cy- Serial No. 713,659. (No nioclelv lindrical extension II for purposes hereinafter describe'd. Air or steam enters at O, passes and repasses through the ports B, and

.her P. (Not shown in the drawings.) The piston A is made integral with the stem F, to which the drills are attached, and is reduced in diameter at the middle, so as to form shoulders m and n, which engage the oscillating tappet I on the forward and backward strokes at c and a, causing said tappet to turn on the pin J and move the valve K accordingly.

On the tappet I is an upright extension terminating in a spherical end L, that fits loosely in a cavityformed in the bottom of the slidevalve K, so that the valve is moved forward and backward by the movements of said tappet, thereloy distributing steam or air to and from the chambers M and N in the usual manner, producing a reciprocating motion of the piston C and a drill attached thereto.

The length of the stroke or range of movement of the piston C and of the drills depends upon the length of the tappet I from c to a compared to the distance between the Shoulders m and n on the piston O. (Shown in the d rawings,approximately,as two to one.)

full stroke, the valve K remains still during` a portion of the stroke or fora distance equal to the difference in length between the points e and a on the tappetand the Shoulders m and n on the piston.

It will be evident that if the distance between 'm and n is shortened the stroke or range of the piston O would be reduced accordingly; but as this is not practicable I provide a supplementary means for moving the valve K in advance of the coming in contact of the shoulder m with the point e of the tappet I. This means, as herein illustrated, consists of a stem Q, pressed elastically against the end of the valve K by a spring R, the force of this spring being sufficient to move the valve K to the right as soon as shoulder a on the piston O passes from beneath the beveled face a of the tappet I. In this manner the stem Q, replaces the function of the tappet I in one direction and admits air or steam to the chamber IT when a portion only of the forward stroke of the piston C is completed. As soon as the pressure of the stem escapes from a port leading from the cham-` When the piston is Operating normally'at,

Q is removed from the valve K this valve and the piston O will resume their full stroke or range.

To apply and remove the elastie pressure of the stem Q requires only that it be detained and loosened at its extreme outward stroke. This I accomplish by any suitable means, preferably by a cam-lever S, that bears on the cap T of the chamber I-I when in the position shown in Fig. I and indicated by dotted lines in Fig. II, holding the stem Q out of contact With the valve K.

To apply the stem Q, and produce short strokes, the lever S is turned as shown in Fig. II, and to prod uce full strokes said lever is turned in the opposite direction, as indicated by dotted lines at U in Fig. II, the change being conveniently made while the machine is in full operation. In this manner it will be seen that the strokes of the piston and the drill can be instantly changed from a full to a partial stroke, or the reverse, greatly adding to the efiiciency and Convenience of Operating, especially in starting holes or in working the drills out when choked.

Having thus described the nature and objects of my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a rock-drilling machine, a main cylinder, a piston, a distributing-valve for air or steam, a tappet to move the valve each Way, and a spring arranged to press against one end of the valve and move it in one direction in advance of the tappefls action, thereby producing short strokes of the piston and of the drills attached thereto, substantially as specified.

2. In a rock-drilling machine, a main cylinder, a piston, a distributing-Valve for air or steam, a tappet to move the slide-valve each way, and a stem pressed elastically against one end of the slide-valve by means of a spring, whereby the valve Will move in one direction in advance of the tappet7s action, and produce short strokes of the piston and of the drills attached thereto, substantially as specified.

3. In a rock-drilling machine, a main cylinder, a piston, a distributing-valve for air or steam, a tappet to operate the slide-valve, a spring to move said valve in one direction in advance of the tappetis action, and means to apply and remove the pressure of the spring, whereby the operation can be instantly changed from a long to a short stroke, and the reverse, substantially as speeified.

XVILLIAH GLEESON. Witnesses:

ALFRED A. ENQUIsT, I-I. W. BROWN. w 

